Fever

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Fever

• Dr C H Asrani

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Fever

• A systematic, non specific defensive response
  caused by infection from bacteria and virus,
  indicated by abnormal high body temperature.

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Fever Mechanism

• Hypothalamus is body's thermostat, usually set at
  37oC.
• Phagocytosis
• Destruction of bacteria and release of LPS
  (lipopolysacchride, an endotoxin)
• Interleukin-1 released by the macrophage reset
  the hypothalamus to a high temp, producing fever
  (body generates extra heat through eg shivering)

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Fever

• Beneficial effects of fever
• Helps set up specific defense (production of T
  cells)
• Speed up metabolism for tissue repair
• Increases the antiviral effect of interferons
• IFNs are a class of anti-vial proteins that
  disrupt viral multiplication
• Not very effective (short-lived and no effect for
  infected cells)
• Nonspecific to viral types

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Fever

• To identify serious cases that require urgent
  treatment or investigation.
• To diagnose the primary disease causing the
  fever.
• To evaluate the need and possibilities of
  treating the underlying cause.
• To evaluate the need for and implementation of
  the treatment of symptomatic fever.

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Fever causes

• Infectious disease is the most common cause of
  fever in primary patient care.
• Other possible causes of fever are inflammatory
  intestinal, joint and connective tissue diseases,
  allergic reactions, malignant tumours and
  hematological diseases.

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Fever Objectives of Rx

• When reducing body temperature, normothermia does
  not need not be the quantitative objective aim
  can be so-called optimal anti pyresis.
• The increased body temperature is reduced to the
  extent that subjective symptoms alleviate but the
  beneficial effects remain.
• In practice this usually means that the body
  temperature decreases by 1 - 1.5ºC, 1 - 2 hours
  after drug administration.

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Fever Symptomatic Rx

• Fever is associated with other symptoms that
  cause considerable discomfort, such as muscle
  pains, headache, nausea, aches, a feeling of
  nausea and noticeable tiredness.
• The fever is markedly high (over 39 - 39.5ºC).

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Fever Symptomatic Rx

• The child has a tendency for febrile convulsions.
  (The rise of fever is prevented by giving
  antipyretic drugs in time. In recurrent febrile
  convulsions diazepam is also used).
• Patient has a serious primary disease, for
  example severe heart, lung or kidney disease. In
  these cases fever may be harmful.

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Fever Beware

• Fever without any clear focal symptoms or focal
  findings
• ? possibility of septicaemia of pneumococcal
  or other aetiology.
• Fever in a child below 3 - 6 mths of age
• ? possibility of serious fulminant disease.
• Observe the child's GC, neurological symptoms
  and alertness. Hospital level investigations are
  usually necessary. If you are treating, ensure
  that parents can contact a doctor easily.

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Fever Beware

• Fever and rash
• Meningococcal septicaemia
• Fever, stomach pain and vomiting
• Appendicitis urinary tract infection.
• Fever and neck pain
• Possibility of a CNS infection.
• Fever and joint pain
• ? purulent joint infection, Rh fever.
• Prolonged fever
• Arrange for further investigations.

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Fever No localizing symptoms

• Identify diseases requiring ASAP Rx (septicaemia,
  meningitis ) and diseases requiring urgent
  treatment in less than 1 day (UTI, pneumonia).
• If GC is poor or the child is irritable on
  touching, a hospital referral indicated.
• Children below the age of 3 yrs should be
  referred to a Paediatrician.

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Fever No symptoms/ Assessing GC

• Use CRP to r/o bacterial infection in children.
  However, CRP may be increased also in viral
  diseases.
• Careful follow-up, eg by frequent telephone
  contacts with the same doctor is necessary if the
  symptoms continue.

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Fever Signs of severe bac inf

• Impaired general condition
• Unwillingness to eat/ drink
• Irritability on touching (even a gentle touch
  makes the child cry)
• Lethargy
• Continuous complaining
• Impaired consciousness
• Petecchiae on the skin

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Fever Investigations

• GC, skin, resp tract the lymph nodes.
• Examine the ears with otoscope to detect acute
  otitis media.
• A urine sample from all with high fever but no
  clear focus of infection.
• CRP, urine test and blood count if there is the
  slightest suspicion of a serious disease. If the
  general condition is good, urine test is
  sufficient as the first examination. CRP and
  blood count are determined if the fever
  continues.

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Fever Investigations

• A chest X-ray in necessary in children whose
  respiratory rate is more than 40/min, whose
  general condition is impaired, or who have
  respiratory difficulty (other than expiratory
  rhonchi alone.

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Fever General Rx

• Sufficient fluid intake
• Light, tasty food
• Avoidance of physical strain. Absolute bed rest
  is not needed.
• Reducing the room temperature artificially or
  removing clothing to the point of discomfort is
  unnecessary and even harmful.

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Fever Medical Rx

• The antipyretic should be taken only when
  necessary. Regular use of fever medication should
  be avoided in all except those children prone to
  febrile convulsions.